Re: [tcmtf] TCM-TF: New Scenarios section

[FERNANDO PASCUAL BLANCO <[e-mail]>]

Hi Jose,

I agree with the scenario classification. It is general enough to englobe the different TCM-TF possibilities. Just a couple of things:


  *   When you say “...with the same destination. As shown in Figure 1, depending on the number..” I think you actually refer to Figure 2.
  *   I have one application scenario in my mind that I´m not able to fit in one of the presented scenarios (but I do in a mix of scenario 1.4.1 and 1.4.2): what about a gaming provider that wants to TCM-optimize it game server connection by establishing associations between its TCM-IO/EO placed in the game server and several TCM-IO/EO placed in different ISPs (agreements would be necessary between the game provider and every ISP)? Let me try by drawing in ASCII:


                              _  _

                             ( `   )_

           +---------+      (    )    `)

 N-users  -|TCM-IO/EO|-->  (_   (_ .  _) _)  --

           +---------+          ISP 2           \

                              _  _               \         _  _                      _  _                                       _  _

                             ( `   )_             \       ( `   )                   ( `   )                                    ( `   )

           +---------+      (    )    `)           \->   (    )    `)              (    )    `)             +---------+       (    )    `)

 M-users  -|TCM-IO/EO|-->  (_   (_ .  _) _)  -------->  (_   (_ .  _) _)  ---->   (_   (_ .  _) _)  ---->  -|TCM-IO/EO|--->  (_   (_ .  _) _)

           +---------+          ISP 3              /->    Internet                     ISP 1                +---------+       Game Provider

                              _  _                /                                     ^

                             ( `   )_            /                                      |

           +---------+      (    )    `)     -- /                                  +---------+

 O-users  -|TCM-IO/EO|-->  (_   (_ .  _) _)                            P-users   --|TCM-IO/EO|

           +---------+          ISP 4                                              +---------+

In every ISP the TCM-IO/EO would be placed in the more appropriate point (actually it could be several TCM-IO/EO per ISP) in order to aggregate the correct number of users (as in scenario 1.4.2).

Do you think it is a useful scenario to describe or it is not necessary assuming that it could be seen as a mix of basic scenarios?

Regards,
Fernando

Fernando Pascual Blanco
Network Automation and Dynamization | Telefonica Global Resources
C/ Don Ramón de la Cruz 82-84, 28006, Madrid, España
[e-mail]<mailto:[e-mail]> |F [phone]  |  M [phone]

On 03/12/2013, at 12:28, Jose Saldana <[e-mail]<mailto:[e-mail]>> wrote:

Hi all. I am working on the next version of the TCM-TF “reference model” draft. I have re-written the Scenarios section, according to David’s classification, and taking into account the discussion of the last weeks. So I would like to hear your opinion.

I have also included three new figures.

Thanks a lot!

Jose


1.4.  Scenarios of application



   Different scenarios of application can be considered for the

   tunneling, compressing and multiplexing solution.  They can be

   classified according to the domains involved in the optimization:



1.4.1.  Multidomain scenario



   In this scenario, the TCMT-TF tunnel goes all the way from one

   network edge to another, and therefore it can cross several domains.

   As shown in Figure 1, the optimization is performed before the

   packets leave the domain of an ISP; the traffic crosses the Internet

   tunnelized, and the packets are rebuilt at the entry of the second

   domain.



      _  _                       _  _                       _  _

     ( `   )_       +------+    ( `   )_       +------+    ( `   )_

    (    )    `)  --|TCM-IO|-->(    )    `)  --|TCM-EO|-->(    )    `)

   (_   (_ .  _) _) +------+  (_   (_ .  _) _) +------+  (_   (_ .  _)_)



        ISP 1                     Internet                   ISP 2



                     <------------TCM-TF-------------->



                                 Figure 1



   Note that this is not from border to border (which could be covered

   with specialized links) but from edge to edge (e.g. managing all

   traffic from individual users arriving at a Game Provider, regardless

   users' location).



1.4.2.  Single domain



   TCM-TF is only activated inside an ISP, from the edge to border,

   inside the network operator.  The geographical scope and network

   depth of TCM-TF activation could be on demand, according to traffic

   conditions.





            +------+

   N users -|TCM-IO|\

            +------+ \

                      \       _  _                        _  _

            +------+   \-->  ( `   )_       +------+     ( `   )_

   M users -|TCM-IO|------> (    )    `)  --|TCM-EO|--> (    )    `)

            +------+   / ->(_   (_ .  _) _) +------+   (_   (_ .  _) _)

                      /

            +------+ /         ISP                        Internet

   P users -|TCM-IO|/

            +------+



               <------------TCM-TF-------------->



                                 Figure 2



   If we consider the residential users of a real-time interactive

   application (e.g., VoIP, an online game generating small packets) in

   a town or a district, a TCM optimizing module can be included in

   network devices, in order to group packets with the same destination.

   As shown in Figure 1, depending on the number of users of the

   application, the packets could be grouped at different levels in DSL

   fixed network scenarios, at gateway level in LTE mobile network

   scenarios or even in other ISP edge routers.  TCM-TF may also be

   applied for fiber residential accesses, and in 2G/3G mobile networks.

   This would reduce bandwidth requirements in the provider aggregation

   network



   At the same time, the ISP would implement TCM-TF capabilities within

   its own MPLS network in order to optimize internal network resources:

   optimizing modules could be embedded in the Label Edge Routers of the

   network.  In that scenario MPLS would be the "tunneling" layer, being

   the tunnels the paths defined by the MPLS labels and avoiding the use

   of other tunneling protocols.



   Finally, some networks use cRTP [cRTP] in order to obtain bandwidth

   savings on the access link, but as a counterpart it consumes

   considerable CPU resources on the aggregation router.  In these

   cases, by means of TCM, instead of only saving bandwidth on the

   access link, it could also be saved across the ISP network, without

   the CPU impact on the aggregation router.



1.4.3.  Private solutions



   End users can also optimize traffic end-to-end from network borders.

   TCM-TF is used to connect private networks geographically apart (e.g.

   corporation headquarters and subsidiaries), without the ISP being

   aware (or having to manage) those flows, as shown in Figure 3, where

   two different locations are connected through a tunnel traversing the

   Internet or another network.



      _  _                       _  _                       _  _

     ( `   )_       +------+    ( `   )_       +------+    ( `   )_

    (    )    `)  --|TCM-IO|-->(    )    `)  --|TCM-EO|-->(    )    `)

   (_   (_ .  _) _) +------+  (_   (_ .  _) _) +------+  (_   (_ .  _)_)



     Location 1                 ISP/Internet                Location 2



                     <------------TCM-TF------------->



                                 Figure 3



   Some examples of these scenarios:



   o  The case of an enterprise with a number of distributed central

      offices, in which an appliance could be placed next to the access

      router, being able to optimize traffic flows with a shared origin

      and destination.  Thus, a number of remote desktop sessions to the

      same server could be optimized, or a number of VoIP calls between

      two offices could also require less bandwidth and fewer packets

      per second.  In some cases the tunnel is already included for

      security reasons, so the additional overhead of TCM-TF is lower.



   o  An Internet cafe, which is suitable of having many users of the

      same application (e.g., VoIP, a game) sharing the same access

      link.  Internet cafes are very popular in countries with

      relatively low access speeds in households, where home computer

      penetration is usually low as well.  In many of these countries,

      bandwidth can become a serious limitation for this kind of

      business, so TCM-TF savings may become interesting for their

      viability.



   o  Community networks [topology_CNs] (typically deployed in rural

      areas or in developing countries), in which a number of people in

      the same geographical place share their connections in a

      cooperative way, and a number of wireless hops are required in

      order to reach a router connected to the Internet.



   o  Satellite communication links that often manage the bandwidth by

      limiting the transmission rate, measured in packets per second

      (pps), to and from the satellite.  Applications like VoIP that

      generate a large number of small packets can easily fill the

      maximum number of pps slots, limiting the throughput across such

      links.  As an example, a G.729a voice call generates 50 pps at 20

      ms packetization time.  If the satellite transmission allows 1,500

      pps, the number of simultaneous voice calls is limited to 30.

      This results in poor utilization of the satellite link's bandwidth

      as well as places a low bound on the number of voice calls that

      can utilize the link simultaneously.  TCM optimization of small

      packets into one packet for transmission would improve the

      efficiency.



   o  In a M2M/SCADA (Supervisory Control And Data Acquisition) context,

      TCM optimization can be applied when a satellite link is used for

      collecting the data of a number of sensors.  M2M terminals are

      normally equipped with sensing devices which can interface to

      proximity sensor networks through wireless connections.  The

      terminal can send the collected sensing data using a satellite

      link connecting to a satellite gateway, which in turn will forward

      the M2M/SCADA data to the to the processing and control center

      through Internet.  The size of typical M2M application transaction

      depends on the specific service and it may vary from a minimum of

      20 bytes (e.g., tracking and metering in private security) to

      about 1,000 bytes (e.g., video-surveillance).  In this context,

      TCM-TF concepts can be also applied to allow a more efficient use

      of the available satellite link capacity, matching the

      requirements demanded by some M2M services.  If the case of large

      sensor deployments is considered, where proximity sensor networks

      transmit data through different satellite terminals, the use of

      compression algorithms already available in current satellite

      systems to reduce the overhead introduced by UDP and IPv6

      protocols is certainly desirable.  In addition to this, tunneling

      and multiplexing functions available from TCM-TF allows extending

      compression functionality throughout the rest the network, to

      eventually reach the processing and control centers.



   o  Desktop or application sharing where the traffic from the server

      to the client typically consists of the delta of screen updates.

      Also, the standard for remote desktop sharing emerging for WebRTC

      in the RTCWEB Working Group is: {something}/SCTP/UDP (Stream

      Control Transmission Protocol [SCTP]).  In this scenario, SCTP/UDP

      could be used in other cases: chatting, file sharing and

      applications related to WebRTC peers.  There could be hundreds of

      clients at a site talking to a server located at a datacenter over

      a WAN.  Compressing, multiplexing and tunneling this traffic could

      save WAN bandwidth and potentially improve latency.



1.4.4.  Mixed scenarios



   Different combinations of the previous scenarios can be considered.

   Agreements between different companies can be established in order to

   save bandwidth and to reduce packets per second.  Some examples:



   o  An ISP could place a TCM optimizer in its aggregation network, in

      order to tunnel all the packets of a service, sending them to the

      application provider, who would rebuild the packets before

      forwarding them to the application server.  This would result in

      savings for both actors.



   o  A service provider (e.g., an online gaming company) could be

      allowed to place a TCM optimizer in the aggregation network of an

      ISP, being able to optimize all the flows of a game or service.

      Another TCM optimizer would rebuild these packets once they arrive

      to the network of the provider.





[topology_CNs] Vega, D., Cerda-Alabern, L., Navarro, L., and R. Meseguer,

              "Topology patterns of a community network: Guifi. net.",

              Proceedings Wireless and Mobile Computing, Networking and

              Communications (WiMob), 2012 IEEE 8th International

              Conference on (pp. 612-619) , 2012.


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